1. Field of the Invention
This invention relates to fluid jet interlace apparatus, and related methods, for interlacing filaments into a yarn with the filaments intermingled with adjacent ones of the filaments and groups of the filaments to maintain unity of the yarn by frictional constraint between the filaments at periodic nodes along the yarn. The invention also relates to methods of making fluid jet interlace apparatus.
2. Description of Related Art
Apparatus and processes for interlacing filaments entangle substantially parallel filaments of a spun yarn thereby periodically producing interlaced portions, knots or nodes in the yarn and substantially non interlaced portions in the yarn. This gives a coherence to the yarn similar to that of a twisted yarn despite the fact that there is hardly any twist, or no twist, in the yarn. Interlacing is now conventional for high speed spinning processes for producing multifilament yarns.
The interlacing of filaments in a yarn was first taught by W. W. Bunting, Jr., et al., in U.S. Pat. No. 2,985,995 which discloses interlace apparatuses having yarn passages with circular cross sections (FIG. 1 therein), rectangular or slot shaped cross sections (FIG. 5 therein) and oval cross sections (FIG. 22 therein).
Interlace apparatuses are commercially available from Fiberguide Ltd., with offices in Cheshire, England, and International Machinery Sales, Inc. (IMS), with offices in Winston Salem, N.C. USA, with yarn passages with various cross sections including triangular cross sections with substantially pointed corners.
U.S. Pat. No. 5,146,660 assigned to Heberlein Maschinenfabrik AG, discloses interlace apparatus having yarn passages with numerous alternative cross sections.
U.S. Pat. No. 5,079,813 assigned to E. I. du Pont de Nemours and Company discloses an interlace apparatus having yarn passages with slot shaped cross sections that flare outwardly from where they intersect air inlet passages.
Some prior art interlace apparatuses produce an insufficient number of interlaced nodes with adequate coherence strength.
Some fluid jet interlace apparatuses are less efficient and require more compressed fluid, typically gas, than other apparatuses, which adds to the cost of the final product. Obviously it is desirable to reduce the amount of fluid needed to produce an acceptable interlaced yarn thereby reducing the cost of the final product.
Certain interlace apparatuses suffer disadvantages associated with threading yarn into the apparatuses. Some apparatuses have a tendency to force fluid from the yarn passage out through the string up slot thereby hindering the feeding of the yarn through a string up slot into the yarn passage. U.S. Pat. No. 5,146,660 discloses apparatus designs to overcome this problem by having special corners built in the yarn passage which provide low pressure areas reducing the force of air out the string up slot.
It is desirable to provide suitable fluid jet interlace apparatuses, and associated methods of interlacing, and methods of manufacturing such apparatus, that solve or improve upon one or more of the above problems.
These and other objects of the invention will be clear from the following description.